Bore-enlarging device



l. H. MILLS.

BORE ENLARGING DEVICE.

APPLICATION FILED 1AN.8. 1919.

Patented Apr. 11, L J0 l INVENToR wlTNl-:ssss:

E BY n u I l i ATTRNEY UNITED stares PA'XENT OFFICE.

ISAAC iL MILLsYor TRTLE GREEK, PENNSYLVANIA.'

BonE-ENLARGING DEVICE.Y

Application led January 8, 1919. Serial No. 270,136.

To all whom t may concern.'

Be it known that I, lsAsc H. MILLS, av citizen of the United States, anda resident of Turtle Creelr, in the county of Allegheny and State ofVPennsylvania, have invented a new and use'liul.Improvement inBore-Enlarging Devices, of which the 'following is a specication.

My invention relates toV metal-Working tools and more particularly tobore enlarging devices, and it has for its primary object the provisionof a bore-enlarging device which will be unusually accurate and whichWill operate upon a bore or scatto 'be enlarged in such manner as toincrease', rather than diminish, the strength "and durabilityof thesurrounding metal ot' which the body is composed.

l Heretofore, to the best olf myrlrnoivledge, bore-enlarging tools, andparticularly those of the reamer type, have been 4formed with oneor morecutting edges or blades which, during the employment ot the tool, cut orscrape away metal from the wall ot the bore Y or recess to be enlargeduntil'such'ibore or recess has been brought to the Vdesired dimensions.Because ot the 'Fact that thecutting edges or bladesot the reamers, otne cessity, become Worn by this'cutting action, itis very diilicult toobtain extreme accuracy, when employing such reamers as, un-

less they are continually measured and ad' justed, they will remove lessand less metal from successive pieces oli vxorlnrso that uni- Y'formityis practically impossible.

Furthermore, reamers ot the cutter type are unsatisfactory for delicatework particularly in sott metals, such as aluminum, on account o'tl thefact that the cutting or scraping avvay of metal trom the Werl; beingoperated upon by the reamers leaves a roughened, more or less pitted andWealtened surface, at the Wall ot the bore or re'- cess being operatedupon, with the result that this surface will be rapidly Worn away whenutilized as a bearing tor a rotating part.

One of the chief objects oit my present invention resides. in theprovision of a boreenlarging device so constructed and employed thatthere is no cutting or scraping away of the metal surrounding the boreor recess being enlargedby the tool. l/Vith a tool thus operating, itis'obvious that the necessity for any cutting edges or blades isavoided, and inaccuracies, such as have previously occurred because ofwearing awa-y of such cutting edges, are -obviated Another object of myinvention consists in providing a bore-enlarging device of suchcharacter that, in place of removing met-al from the 'Wall of theopening being enlarged, the metal constituting the wall is compressed orforced outwardly so that the surface of the opening is rendered bothsmooth and hard, and the met-al constituting it is rendered more denseand, consequently, more resistant to Wear. y

Vth these objects in View, I have provided a bore-enlarging device`which, broadly speaking, comprises. a cage having a plurality ofcircumferentially spaced bearing pins about which are loosely mountedcompression rollers adapted to engage the Wall of the opening beingenlarged and to roll along the surface oi' the Wall. My inventioncomprises also. a readily adjustable means for forcing the rollers in anoutward radial direction so that the compressive action exerted by themupon the Wall of the opening being enlarged may be increased, from timeto time, as the size of the open ing is increased through compressionoit the v material surrounding it. Preferably, the adjusting meansincludes a vernier in its construction in order that' all adjustmentsmay be'made with extreme accuracy and to any desired predeterminedextent.

In the drawings,- Which illustrate a pre- -ferred' form of my inventionyand in the several views ot which Vsimilar reference numerals indicatecorresponding parts, Fig. l is aside elevational view, partially Vinsection on the line I l of Fig. Fig. 2 a horizontal sectional view takenon the line IIe-II of Fig. l; and Fig. 3 is an elevation, partially insection, ot a split expansihle sleeve4 forming a portion of the adjustinmechanism of the tool.

ei'erring more particularly to Fig. l of the drawings, l designates asuitable mandrel Which may be provided, adjacent one end, With adiametrally extending handle 2 and, at its other end, with atruste-conical expander-head 3 having a centrally located,cylindricalrecess 4f in its outer face. Surroundingthe expander-head 3isa split expansible sleeve 5 which isk externally cylindrical in shapeand the inner face of which is inclined to uniformly engage the inclinedface ot the Aexpander-head. The sleeve 5 Whichlmay be formed of anysuitable resilient metal, may be split by a slot 6 which is preferablyvdiagonally disposed, as shown in Fig. 3,' in order that there shall beno continuous vertical brealnfrom top to bottom. As a means for insuringturning of the sleeve, together with the mandrel, while, at the sametime, permit-ting longitudinal movement of the sleeve alongvtheexpanderhead 3 of the mandrel, l may provide diametrally disposed pins"Z which project from the expander-head and seat in vertically disposedslots 8 formed in the sleeve.`

Surrounding the sleeve is a cage comprising a bottom plate 9 and a topring 1() connected and maintained in proper spaced relation by spacerpins 11, circumferentially disposed as shown in Fig. 2. The ends of thespacer pinsll are shouldered, as indicated at 12, and their reduced endsare passed through openings in the plate 9 and ring 10 and upset, asclearly indicated in Fig. 1. The cage, at its lower portion, may becentralized by a boss 13 formed upon the botf tom plate 9 and seated inthe recess 4 of the expander-head and the cage may be secured, forturning movement about the expanderhead 3 and its surrounding sleeve 5by means of a shouldered screw 15, passed loosely through a washer 16and theV bottomplate 9 and threaded axially into the lower face oftheeXpander-head. Preferably, the engaging faces of the bottom plate 9and washer 16 are formed with opposed annular channels to provide a racefor bearing balls 1'?.v f

An adjusting nut 18 has threaded engagement with a portion ofthe mandrelabove the expander-head 3, as indicated at 19, and is provided withhandles 2O by means of which it may be readily turned. The adjust ingnut 18, near its lower end, has a reduced portion 20fL to snugly receivethe top ring 10 of the cage and a further reduced portion 21 upon whichis shrunk a bearing ring 22 which engages the upper edge of theexpansible sleeve 5, the latter sleeve being held, at all times, inengagement with this ring by a resilient washer 23 interposed betweenthe lower edge of the ring and the plate 9 and'preferably, also engaginga peripheral seat 24 formedV inthe lower end of the eX pander-head 3. lj

A plurality of bearing pins 25 are provided with reduced ends 26 whichare passed.

` upwardly through spaced, circumferentially disposed openings in thetop ring '10 of the cage and are upset, as kshown in Fig. 1, to securethem in place. The lower ends of vthe bearing pins 25 are formed withheads 27 which serve as retaining means for compression rollers 28 whichare loosely mounted about the bearing pins in such manner as to haveconsiderable play or movement radially, with respect to the cage, theprovision for this movement beingclearly disthis variation in spacingneed not be great,

as will be later appreciated when the reason for it is explained.

The upper portion of the adjusting nut 18 tapers uniformly' to themandrel 1 to provide a suitable surface for the radial divisions of onescale section 29 which co-operates with the longitudinally'spaceddivisions of another scale section 30 inscribed upon the mandrel 1, toprovide a vernier by whic an extremely accurate settingof the. tool maybe attained, as will be subsequently pointed out.

When my device is to be employed in enlarging a bearing opening orrecessin a certain pieceof work, the adjusting nut-1S may be turned in acounter-clockwise direction so that the eXpansible sleeve 5, maycontract and move upwardly along the inclined surface vof theexpander-head 3, of the mandrel until the compression rollers 28, whichengage the outer surface of the sleeve, are moved inwardly to asul'licient extent to permit the positioning of the operating head or"the tool within the opening or recess to be enlarged, with the outerportions ofthe compression rollers in engagement withk the wall of suchopening.

The adjusting nut 18 may then be turned in the reverse direction, themandrel in the meantime being held against turning movement, until theexpansible sleeve 5 has been forced downwardly upon the expander-head 3and soenpanded as to force the rollers 28 into compressiveAengagementwith the wall of the opening to be enlarged. When this hasbeen accomplished, thedmandrel 1 may be turned, in either direction, asmay be convenient. This turning of the mandrel causes' a correspondingturning of the sleeve 5 and, because of the frictional engagement of thevarious parte, the cage will turn with the mandrel. and sleeveso thatthe compression rollersL will roll along the face of the opening beingenlarged, to compress the metal er other material surrounding theopening. as will be readily appreciated. From time to time, as theoperation proceeds,

lthe adjusting nutidmay be further turned in a clockwise direction tocause an outward radial advance of the compression rollers so that theopening may be continuously enlarged, until. as indicated by theco-operating scale sections of the Vernier, the desired size has beenreached.`

Because of the non-uniform circumferential spacing of the compressionrollers. there is no tendency for the rollers to forml a series ofdepressions in the wall of the opening being enlarged, in which theymight, in time, come to roll idly as the manllO drel was turned insteadof being carried about with it.

F rom the foregoing description or" the construction and the method or'employing my bore-enlarging device, it will be appreciated thatextremely accurate work may be continuously turned out, as there are nocutting edges or blades which will wear away.V Furthermore, considerabletime and labor may be saved, by the employment oi my invention, becauseof the fact that there are no portions requiring special attention, suchis the case with cutter-reamers which must be sharpened, from time totime. However, one or' the chief advantages developing from theemployment of my device resides in the tact that, instead of removingmetal from the wall ot the opening being treated and thus producing arough, pitted and weakened surface, particularly when the metal isrelatively soft, the metal constituting the wall ot the opening iscompressed, rendered more dense and hardened and given an extremelysmooth and polished surface that is highly resistant to wear.

ln many instances, the tool may be employed in enlargingbearing-receiving recesses formed in the wall ot a body, about ashaft-receiving opening formed therein, and it is for this reason that Ihave provided -a ball-bearing between the bottom plate ot the cage andthe washer engaging' it so that, in cases where the washer may engageagainst the inner wall ot' a recess being enlarged, the cage may turnfreely while the washer may remain stationary and,

asa consequence, cannot injure or wear i away the metal constituting theinner wall ot the recess. i

Although .l have illustrated `but a single vembodiment oit' my inventionand have,

moreover,V described this embodiment in considerable detail, it will beappreciated that my invention is ot such scope as; to cover similaiorequivalent constructions. and is to be restricted vonly as indicated inthe claims.

I claim as my invention:

l. A bore-enlarging device including a rotatable mandrel, anexpander-head forming one end` ot the mandrel, a cage surrounding theexpander-head to rotate with the head and mandrel, compression rollerscarried by the cage and disposed circumferentially oi' the expander-headand means cooperating with'the expander-head tor 'forcing the rollersoutwardly.

2. A bore-enlarging device including a rotatable mandrel provided, atone end, with an expander-head, an eXpansible sleeve carried by the headto rotate therewith and adapted to be expanded and contracted throughengagement with the head when reciprocated relative thereto, a cagesurrounding the expander-head and sleeve and adapted to turn therewith,rollers carried by the cage and mounted for limited outward movement,the rollers being engageable by the sleeve, and means for adjustablyreciprocating the sleeve to cause such movement of the rollers.

A bore-enlarging device including a mandrel provided with a taperedexpanderhead, an expansible sleeve mounted about the head and expansiblethrough relative longitudinal movement therebetween, adjustable meansfor causing relative movement ot' the expander-head and sleeve, andcompres- Ision members disposed about, and in engagement with, thesleeve.

ll. J bore-enlargin device including` a mandrel provided wit a taperedexpanderliead, an expansible sleeve mounted about the head andexpansible through relative longitudinal movement therebetween,adjustable means for causing relative movement oi the expander-head andsleeve, and compression rollers supported about the sleeve tor outwardradial movement during expansion oi the sleeve.

5. A bore-enlarging device including` a rotatable member. an expansiblemember disposed ther'eabout, means (zo-operating between the members,'tor expanding the expansible member, and a plurality ot compressionmembers surrounding the expansible member and movable outwardly uponexpansion thereof.

6. A bore-enlarging device including a series of compression rollerscircumferentially disposed at unequal intervals, means for moving therollers in a circular path about their common axis and means toradjusting the rollers radially relative to such axis.

7. A bore-enlarging device including a rotatable mandrel, a cage mountedto rotate with the mandrel, compression rollers carried by the cagecircumterentially disposed at unequal intervals and means tor moving therollers toward and away from the mandiel.

y8. A bore-enlarging device including a rotatable mandrel, a cagemounted to rotate with the mandrel, an end plate rotatably mounted uponthe cage, oircumterentially disposed compression rollers carried by thecage and means tor moving the rollers toward and away trom the mandrel.

In testimony whereof, I' have hereunto subscribed my naine this 27th dayot Dec.. 1918.

ISAAC H. MILLS.

